CHAPTER XXIII. 

 UTILIZATION AND RECLAMATION OF ALKALI LANDS. 



Alkali-Resistant Crops. The most obvious mode of utiliz- 

 ing alkali lands is to occupy them with crops not affected by the 

 noxious salts. Unfortunately but few such crops of general 

 utility have as yet been found for the stronger class of alkali 

 lands. The question is always one of degree, which frequently 

 cannot be decided without an actual determination of the 

 amount and kind of salts to be dealt with, to which the crops 

 can then be adapted in accordance with the greater or less sensi- 

 tiveness of the several plants, as indicated in the table of toler- 

 ances given farther on. But aside from this, there are certain 

 general measures and precautions which in any case will serve 

 to mitigate the effect of the alkali salts. Foremost among 

 these, and applicable everywhere, is the prevention of evapora- 

 tion to the utmost extent possible. 



Counteracting Evaporation. Since evaporation of the soil- 

 moisture at the surface is what brings the alkali to the level 

 where the main injury to plants occurs, it is obvious that evapo- 

 ration should be prevented as much as possible. This is the 

 more important, as the saving of soil-moisture, and therefore 

 of irrigation water, is attainable by the same means. 



Three methods for this purpose arc usually practiced, viz., 

 shading, mulching, and the maintenance of loose tilth in the 

 surface soil to such depth as may be required by the climatic 

 conditions. 



As to mulching, it is already well recognized in the alkali 

 regions of California as an effective remedy in light cases. 

 Fruit trees are frequently thus protected, particularly while 

 young, after which their shade alone may ( as in the case of 

 low-trained orange trees) suffice to prevent injury. The same 

 often happens in the case of low-trained vines, small-fruit, and 

 vegetables. Sanding of the surface to the depth of several 

 inches was among the first attempts in this direction; but the 



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